Hi,
I know that " The output capacitance of the IC which is driving must be greater than the input capacitance of the IC which is being driven. ( Load Analysis). But I want to know as Why this is required? And also any links which will help me in this.

hi,
The input impedance of the driven IC (or driven stage) need to be of greater order than the output impedance of the driving IC (or driving stage) for little loading effects on the signals being transmitted from one IC (or stage) to the other IC (or stage). Almost any electronic signal is actually a voltage signal that must not undergo much voltage drop along its path in travelling down the PCB tracks. If you apply the voltage devider rule on the network linking the two IC's (or stages) you see that a higher input impedance on the driven circuit compared to the output impedance of the driving impedance would keep the signal at the output of the driving IC close to the desired value (as needed in our theoritical block diagram analysis).